Explosive



Feb. 17, 1942.

R. C. ALLEN EXPLQSIVE Filed May 13, 1939 2 Sheets-Sheet l BY I a A9 ATTORNEYS.

2 Sheets-Sheet 2 A V 1 A ROBERT c. ALLEN R. C. ALLEN EXPLOS IVE Filed May 13, 1939 Feb. 17, 1942.

Patented Feb. 17, 1942 Claims.

This invention relates, as indicated, to explosives and more particularly to a new and improved explosive device capable of detonation with extreme violence and especially adapted to be employed in aerial bombs, depth bombs, torpedoes and the like, as well as for the usual industrial purposes.

Attempts have been made in the past to employ certain liquefied gases in explosive devices since a large quantity of the gas may thus be made available for explosive combination. Others have employed a liquefied gas in conjunction with the usual explosive materials, the liquefied gas adding to the-force of the explosion only by its expansion to a gaseous state. It is, however, obvious that mixtures of gases capable of explosive combination are extremely dangerous to handle even when the mixture is in the liquid state, certain of such mixtures being very susceptible to shock. Also, any leakage of the mixture would provide a most serious hazard.

It is, therefore, a principal object of my invention to provide an explosive device adapted to utilize the explosive combination of different gases, without endangering those employing the device, such gases being contained in said device in a liquid state prior to the time of detonation.

Another object is to provide an explosive charge comprising two or more liquefied gases capable of explosive combination when intermingled and a shattering charge adapted to cause such intermingling.

A further object is to-provide a new and improved explosive device suitable for use in aerial bombs and the like and adapted to employ liquefied gases as the primary explosive charge.

Other objects of my invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawings and the following description set forth in detail certain structure and mechanism embodying the invention, such disclosed means constituting, however, but one of various forms in which the principle of the invention may be used.

In said annexed drawings:

Fig. 1 is a View in cross-section of a form of my new device adapted for, use with liquefied gases, the liquefaction temperatures of which are of the same order.

Fig. 2 is an end view of the device of Fig. 1, BB

partly in cross-section, taken along the line 2-2 with a portion broken away to show the concentric arrangement of the chambers.

Fig. 3 is a transverse cross-sectional view of the device of Fig. 1 taken along the line 33.

Fig. 4 is a view in cross-section of a form of my new device adapted to be employed when the liquefaction temperatures of the various liquefied gases are somewhat further apart.

Fig. 5 is an end view of the device of Fig. 4, Partly in cross-section, taken along the line 5-5, with a portion broken away to show the concentric arrangement of the chambers.

Fig. 6 is a transverse cross-sectional view of the device of Fig. 4, taken along the line 6--6.

Fig. 7 shows head and tail pieces in crosssection, attached to the device or my invention and more particularly that form shown in Fig. 10.

Fig. 8 shows, partly in cross-section, a holder and firing head employing a high explosive shell as the shattering means.

Fig. 9 is a cross-sectional view of a delayed action head which may be employed when a moment of time is desired between the instant of contact and instant of explosion.

Fig. 10 is a view in cross-section of a type of my new device in which the expansion of a portion of one gas may be utilized to refrigerate the other (or others).

Fig. 11 is an end view of the device of Fig. 10, partly in cross section, taken along the line llll and with a portion broken away to show the manner in which the chambers are arranged.

Fig. 12 is a transverse cross-sectional view of the device of Fig.10, taken along the line l2-i2.

Fig, 13 is an enlarged cross-sectional view of a constant pressure valve providing an outlet from one o! the chambers containing a liquefied gas.

Fig. 14 is a cross-sectional view of an expansion orifice through which the gas passes in cooling the chambers.

Broadly stated, this invention contemplates the use of liquefied gases or non-explosive mixtures thereof which, when intermingled, are capable of explosive combination, and devices adapted to retain such liquid gases and release the same as desired. This invention also contemplates the use of certain explosive mixtures of gases in liquid form when employed in certain forms of my new device herein described.

The forms of my device shown in the attached drawings are designed ioruse as aerial bombs but it is, or course, obvious that various modifications may be employed for a wide variety or purposes.

Referring now more particularly to the drawhugs and especially Figs. 1, 2 and 3, one preferred embodiment of my new device comprises an outer shell i into which an inner unit 2 is tightly screwed by means of threads on its outer rim and inside the lip 3 of' said outer shell. The tail 8 of said inner unit is tipped with a section of insulating material 5 which in turn fits in a recess 8 in the end of said outer shell. A central chamber 1 formed. in said inner unit is encircled by a radially concentric chamber 8 which also encompasses one end thereof. A third radially concentric chamber 8 encircles the aforesaid chambers and communicates with the outer atmosphere by means of a constant pressure escape valve ill and an intake valve Between the outer wall of said inner unit and the inner wall of said outer shell, another chamber I2 is formed which communicates with the outer atmosphere by means of the valve B. The chamber 8 communicates with the outer atmosphere by way of intake valve I4 and constant pressure escape valve IS. The central chamber E is open to the fiat exterior surface of the inner unit and a pipe l6 preferably of an insulating material is screwed into the opening.

A wall il extends from the flat face of the inner unit 2 and a dome ,I8 is tightly fitted thereabout to form an air-tight chamber IS. A tube 28 connects valve l with the exterior and similar tubes lead from valve l and to valves ii and I. A filler plate 2| is screwed into the head of the dome l8 carrying a detonator 22 and a firing piece 23. Another filler plate 21 with detonator 28 and firing piece 28 screws into chamber l2 by way of a hole tapped in the fiat iaceof inner'unit 2. A valve 30 communicates with chamber l9, wire mesh fabric enclosing the inner terminus 8| of the tube 82.

The entire unit above described is, designed to be employed in an aerial bomb, 9. tsil-piece being attached to the upper end as shown in Fig. 1 and a firing-head placed over the domed head of the unit and secured in place bIshearscrews which enter tapped holes 24, 25 and 2G equally spaced about said unit. g

The above described unit is filled or loaded in the following manner: A gas such as oxygen is compressed and passed through intakevalve id into chamber 8, whence it escapes by way of constant pressure valve IS. The gas is circulated in this manner until chamber 8 is chilled to below the liquefaction temperature of the gas at the pressure maintained by said constant pressure valve. Until such temperature is reached, said constant pressure valve is kept open by means of the device illustrated in Fig. 13 and more fully described below. Then the gas inliquefled condition is passed into chamber 8 through valve ll until said chamber is nearly filled and valve I4 is closed.

" The walls of chamber 8 have likewise been chilled by the removal of heat in chamber a and a liquefied combustible gas, preferably having a liquefaction temperature at the pressure maintained by constant pressure valve ID no I lower than that already attained in chamberzQ, :is passed into chamber 9 by way of valve which is then closed. It will thus be seen that the controlled evaporation of the liquefied gas in chamber 8 acts to maintain the necessary low temperature of the liquefied gases in chambers 8 and 9.

The inner unit 2 is then rested on its tail-end 4| and insulating material such as kieselguhr is placed about the outer surface of said inner unit as shown by the dot and dash lines in Fig. 1, being held in place by a fabric cover. Said inner unit is then screwed tightly in place in the outer shell I and a dry high explosive introduced through ports provided by the removal of filler plates 21, 33 and 84 (not shown), equally spaced and each provided with a detonator and a firing-piece which is not inserted until later.

,Said filler plates are then replaced and the and held in place "by a fabric cover (indicated 7 by dot and dash line) retained in position by an expanding hoop inside said wall and a contracting hoop about said pipe.

The dome I8 is then secured in place and made airtight. Filler plate II is removed and the dome filled with dry explosive, flash powder and pyrotechnic force shells. The filler plate with detonator 2! in place is then reinserted and sealed. Chamber I9 is then exhausted of air to within practical limits by connecting valve 30 to a vacuum line.

While kept in storage as a filled unit, valves Hi and are kept connected to the vacuum line and constant pressure valve ii to a receiver for the gas in chamber 8 which is recompressed and returned when necessary.

when prepared for "active" transit and use the vacuum line is disconnected from valves l8 and 80 which are closed and constant pressure valve l5 is disconnected from the receiver. Firing pieces such as 28 are inserted in the three filler plates of chamber l2 and in filler plate 2| of the dome l8. A firing-head such as firinghead 85 shown in Fig. 7 is then placed over the head of the unit and secured to it by shearscrews which enter tapped holes 24, 25 and 25. A conventional tail-piece such as tail-piece 36 shown in fragmentary cross-section in Fig. 7 and omitting the tail firing pin may then be secured to the rear of the unit.

Another embodiment of my invention generally similar to that above-described but designed for employment with liquid gases having a greater disparity of liquefaction temperatures is illustrated in Figs. 4, 5 and 6. In this form of my new device chamber 9a is separated from chamber 8a not merely by the metal wall of the chamber but by an extension of chamber I211. Insulating material is packed into this intervening area and extends to the point indicated by the dot and dash line. In this case, also, the valve l8a, by which the air is exhausted from chamber Ha, leads to the above-mentioned extension of chamber |2a through a tube 31 passing through wall Ila. Otherwise, as indicated by like numerals, the construction is similar to that shown in Fig. 1 and it is assembled and charged in a like manner.

The device shown in Figs. 10, 11 and 12 is a somewhat more elaborate embodiment of my invention adapted to employ the vaporization and expansion of -a portion of one liquefied gas (or mixture of gases) to maintain the necessary low temperature for a considerable period of time during active transit. In this form the outer section of the unit comprises chambers in and b, a filler plate 38 with detonator 39 screwing into chamber lib at the rear. A firing-piece 40 is inserted prior to preparing for action. Bosses 8i and 82 (the latter shown in elevation in Fig. connect the inner and outer walls of chamber 02b. By means of the hole closed by the filler plate 38, chamber H1) is completely filled with a dry or liquid high explosive and said filler-plate and detonator replaced. Three other detonators such as 28b are equally spaced about the other end of chamber l2b with provision for firing pieces 2%, M and 42 to be later insorted.

Into said outer section is screwed the inner unit comprising chambers lb and 8b with small inter:

connecting chambers 43 disposed therebetween. Between the two sections of the complete unit is formed a chamber 58. In the unit shown in Figs. 10 and 11 there are eight chambers 83 con-' necting at one end as shown in Fig. 10 and at the other end by tubes M. Thus, gas in chamber 8b may, upon vaporizing, pass through tube i5 and constant pressure valve 86 so entering chambers 83 and expanding. It then passes through connecting chambers 48 until it reaches outlet tube 8i and constant pressure valve 48 (see Fig. 11) through which it passes into the atmosphere if the unit is in active transit or into a receiving tank if the unit is in filled storage. The gas is forced to take such a circuitous route through interconnecting chambers 43 due to the fact that there is no direct connection between the chamber entered through constant pressure valve 46 and the chamber from which the tube 81 leads. While thus relieving the pressure within chamber 8b, a refrigerating effect is also obtained, first cooling the chambers and then aiding in maintaining the gases in a liquid state.

As shown in Figs. 10 and 11, the chambers 8b, 9b and 58 may be strengthened by ribs 9, to and Bi respectively. Also, the form of device illustrated in Figs, 1 and 3 may be strengthened by ribs or fins 52 to brace the tail part 5 of the inner unit.

The gas is introduced to chamber 82) by way of valve 53 and circulated as above-described until said chamber is cooled to below the liquefaction temperature of the gas, whereupon the gas is introduced in a liquid state until the chamber is nearly full.

Chamber 8!) is then likewise filled with a liquefled gas by way of valve 54, the air in the chamber escaping through constant pressure valve 55. Chamber 58 is filled with an insulating material through the ports closed by filler plates 56 and 57, which filler plates are then replaced and sealed. Valve 58 is connected to a vacuum line and the air is thus removed from chamber 58 within practical limits.

Chamber lb is filled with flash powder and dry explosive and force" powder-filled shells in the same manner as that described above in connection with the device of Fig. 1 and the dome i8?) is affixed, filled and evacuated oi. air in the same manner. When prepared for active" transit or use, the vacuum line is disconnected from valves 5t and 30b and constant pressure valve lit is disconnected from the gas receiver. Firing-pieces M, 2917, M, M and 231) are inserted and firing-head 35 secured in place as shown in Fig. 7. Said firing-head carries a stiff firing-plate 68 which acts on firing-piece 23b and three shoulders 8! (one only shown) which act on firingpieces 2%, 8i and 82. Tail-piece 36 is next secured to the rear of the unit, said tail-piece, when employed in conjunction with a unit of the type illustrated in Fig. 10, having a firing-pin 82 located in slide-way 63 in which it is held by stoppin 64. A spring prevents contact with firingpiece Ml except upon sudden cessation of forward movement of the bomb.

Fig. 13 illustrates a typical constant pressure valve and more particularly valve 48 and tube 45 shown in Figs. 10 and 11. The valve is conventional in having spring means of a proper degree of resiliency and strength which ordinarily holds the valve-head tightly against the valve-seat until sufllcient pressure is built up to overcome the tension of the spring. However, when it is desired to keep the valve open while circulating through the gas for the purpose of cooling the chambers. this end may be attained by rotating handle 66 causing the valve to be forced open and so maintained.

Fig. 14 illustrates an expansion orifice of the type connecting the chambers 43. Such orifices are located at the points where tubes 44 enter said chambers, th openings 61 being sufilciently small to ensure that the pressure in said chambers is progressively reduced as the gas passes through. Thus, a more uniform refrigeration is obtained. Also, similar expansion orifices may be employed after each of the constant pressure valves to prevent too rapid expansion of the gas. With certain gases or combinations of gases such expansion orifices may be employed in place of certain of the constant pressure valves entirely. if proper precautions are taken.

Fig. 8 illustrates an alternative form of holder and firing-head comprising a dome 68 with firing-piece 69 attached to the holder 18 in which a high explosive shell H is positioned and employed as the primary shattering means.

Fig, 9 illustrates a form of delayed action head suitable for employment with my new explosive unit when it is desired to penetrate some barrier, such as the deck of a battle-ship or the roof of a building prior to the detonation of the primary explosive charge. Said head comprises a shotfilled cartridge 12 which is fired by striker-point 13 of rod 14 when actuated by contact-point 75. The disk 16 attached to rod 14 and acting on spring 11 otherwise prevents contact between said striker-point and the percussion primer of cartridge 12, said cartridge being secured in cylinder head 18. Inserted in cylinder 19 is a container comprising compartments 88 and 8|, compartment 88 having a cylindrical core 82 extending part way into its center portion to house cartridge I2. Cylinder head 83 is of relatively weak and shatterable construction.

A rod 88 connects said head 83 to the piston 85 which is otherwise slidable in cylinder 85 and is secured to striker plate 81 adapted to contact firing-pieces 23, 29, etc. The body of the firinghead comprises threaded sections 88 and 88 enclosing the above-described acting parts.

Chamber 88 contains calcium carbide and chamber 8! water and an anti-freeze constituent. When contact point 15 is forcibly driven back, striker point 13 causes the detonation of cartridge 12 shooting steel balls through partition 90. Acetylene gas is at once generated by the resultant mixture of calcium carbide and water and a rapidly increasing pressure results until cylinder head 83 is violently ruptured and the liberated gas drives piston 85 back causing the firing-pieces 23, 29, etc. to be actuated and setting off the detonators,

When units such as those shown in Figs. 1, 4

causes the threescrews in tapped holes N, 25

and 25 to be sheared and firing-plate BI to strike. firing-piece 23. The shoulders 8|; attached the inner surface oi firing-head ll strike the I and 10 are employed with firing-heads of the type illustrated in Fig. .7, contact withth'e objective of. the gas necessary to make an explosive mixture shoe with this invention.

three firing-pieces such as ilvvl'aich communl-i1-. v

cats with the detonators hi -chamber 12.- The explosive charges inchambers llandj-gand irr dome is serve to shatter the unit and intermingle 1- the contents, the resultant heat 01' combustion supplying heat for vaporization. of the liquid gases and the shells of pyrotechnic force powder ensuring complete ignition. As described ended metal shells ignites any unconsumed combustibles.

While certain approved structures have been pieces provides a unit suitable for industrial purposes.

while it is generally preferred that the constituents capableof explosive combination be separately confinedas a matter both of expediency and safety, a mixture of liquefied gases capable of explosive combination may be employed in my new'device, if so desired. In such case, the other liquid gas chamber should contain a liquefied gas having a lower liquefaction temperature than the aforesaid mixture so that said mixture will be maintained in a liquid state without loss of vapor, at least until said liquefied refrigerant gas has been substantially exhausted. Obviously, such a charge is much more dangerous to those handling it than those previously mentioned. The refrigerating gas may be liquid air, oxygen, ammonia, nitrous oxide, etc., depending on the boiling point of the explosive mixture employed, and need not, of course, be a gas which will combine with said mixture. 0! the forms of my device illustrated, that of Fig. 10, or a modification thereoi is best suited for this purpose, although those of Figs. 1 and 4 may be employed where the charge will be in "active" transit for a shorter period or time.

One approved modification of the device of Fig. 10 suitable for use with explosive mixtures has a chamber in the center for a refrigerating gas with expansion chambers disposed around it. Next is a radially concentric chamber for the explosive mixture and finally a surrounding chamber for insulation. Detonators may be located in the chamber containing the explosive mixture wire gauze just within the outlets from the cham- Among the gases which may be liquefied employed in accordance with my invention are the following. It will, of course, be understood that the following list is given for purposes of illustration only and with no intention of limiting the invention to these particular examples.

I. Combustible gases:

Ethane Hydrogen sulphide Methyl ether Methyl chloride Tetramethyl methane Trimethylene Acetylene Propane Iso-butane Carbon monoxide Methane Hydrogen II. oxidizing gases:

' Air Oxygen Ozone bers containing combustible gases and particularlyso in the case of explosive. mixtures. This minimizes danger of accidental explosion.

While it ls generally contemplated that the oxidizing gas or gases will be confined in chambers I, la and 8b and the combustible gas or gases in chambers 9, 0a and so, it will be understood that this arrangement may be reversed, if so desired, as by having hydrogen in 8b and oxygen in Ob. when non-explosive mixtures of oxidizing and combustible liquefied gases are employed, such mixtures will generally be confined in chambers I, to and 9b and the proper gas or gases to form an explosive admixture therewith in chambers 3, 8a and 8b. a

It is generally preierable that a mixture of oxidizing and combustible gases, whether in explosive or non-explosive proportions, be preserved with little or no loss of vapor since, for example, a mixture of methane and lnsuflicient oxygen to form an explosive mixture might on escaping into the atmosphere be there capable of explosive ignition due to the presence of additional oxygen. It is for this reason that the refrigerating-gas is employed in chamber 8b (Fig. 10), since ithmay be permitted to escape with no untowardresult, while, on the other hand, the mixture of oxidizing and combustible gases is confined lnchamber 9b where (having a higher liquefaction temperature, or boiling-point, than the gas in chamber Oh) it remains until the gas in chamber 8b has evaporated. Also, when a non-explosive. mixture of an oxidizing and a combustible gas is employed, it may be desirable to employ a deficiency of the more volatile gas so as to ensure that an explosive ratio is not obtained by partial evaporation during active" transit.

Inert gases such as nitrogen and others such as ammonia may be employed as refrigerants or mixed with the more active constituents, such as a mixture of liquid air and liquefied oxygen.

Among the changes which may obviously-be made in the forms of my new device illustrated in the drawings are a rearrangement of the chambers to provide for further insulation, or, in the device of Fig. 10, locating chamber 9b more closely adjacent chamber 8b to provide for more efiicient refrigeration, or by placing chambers 43 between chambers 817 and 8b for more complete refrigeration, the insulation being placed about the exterior wall of chamber 9b. In general, a great many variations are clearly possible and may be desirable to obtain the best results with any specified combination of gases.

Other forms may be employed embodying the features of my invention instead of the one here explained, change being made in the form or construction or constituents employed, provided the elements stated by any of the followingv claims or the equivalents of such stated elements be employed. 7

I therefore particularly point out and distinctly claim as my invention:

1. An explosive device comprising a unit including a central chamber containing a shatter.- ing charge, a radially concentric chamber containing a liquefied gas, another radially concentric chamber adjacent thereto and connecting therewith to permit evaporation of some of said liquefied gas for refrigerating purposes.

2. An explosive device comprising a series of substantially concentric chambers, liquefied gases separately confined in certain of said chambers and capable of explosive combination when intermingled, means permitting controlled evaporation of at least one of said gases, and a shattering charge in one of saidchambers adapted to cause such intermingling.

3. An explosive device comprising a series of substantially concentric chambers, liquefied gases separately confined in certain of said,

chambers and capable of explosive combination when intermingled, means permitting controlled evaporation of at least one of said gases, an ignition charge, and a shattering charge adapted to cause such intermingling.

4. An explosive device comprising a unit including a central chamber containing a shattering charge, a radially concentric chamber contraining a liquefied gas, another radially concentric chamber adjacent thereto and connectin therewith to permit of evaporation of said liquefied gas, another radially concentric chamber containing a liquefied gas capable of explosive combination with said first mentioned liquefied gas when intermingled therewith, and heat insulating means protecting said unit.

- ,5. An explosive device comprising a unit including a central chamber containing a shattering charge, a radially concentric chamber containing a liquefied gas, another radially concentric chamber adjacent thereto and connecting therewith to permit of evaporation of said liquefied gas, another radially concentric chamber containing a liquefied gas capable of explosive combination with said'i'lrst mentioned liquefied gas when intermingled therewith, heat insulating means protecting said unit, and means for detonating said shattering charge and igniting the resultant mixture of gases.

6. An explosive device comprising a unit including a central chamber containing a shattering charge, a radially concentric chamber containing a liquefied gas, another radially concentric chamber adjacent thereto and connecting therewith through a constant pressure valve, another radially concentric chamber containing a liquefied gas capable of explosive combination with said first-mentioned gas when intermingled therewith, and heat insulating means protecting said unit.

7. An explosive device comprising a unit in cluding a central chamber containing a high explosive, radially concentric chambers containing liquefied gases capable of forming an explosive mixture when intermingled, an outer chamber containing a high explosive, and a vacuumed chamber substantially surrounding said unit.

8. An explosive device comprising a unit including a central chamber containing a high explosive, a radially concentric chamber containing a liquefied gas, a radially concentric expansion chamber communicating with said last named chamber, a radially concentric chamber containing a liquefied gas capable of explosive combination with said first mentionedgas when intermingled therewith, an insulating chamber substantially enclosing said first mentioned concentric chamber, and an outer chamber containing a shattering charge.

9. An explosive device comprising a unit including a central chamber containing a high explosive, a radially concentric chamber containing a liquefied gas,'a radially concentric expansion chamber communicating with said last named chamber by way of a constant pressure valve and also having an outlet to the outer air,

another chamber partially enclosing said previ-' ously mentioned chambers and provided with in.-

ber partially enclosing saldsecond concentric removed.v

chamber and adapted to have the air therefrom within practical limits.

ROBERT C. ALLEN. 

